To get the info on this extremely rare Russian Imperial Plate by Popov Factory which was bought at Sotheby's on June 12, 2007, for $26,060 please see the link below:
A few underglaze hairlines (picture #3) on the right side of the Blue Popov mark are factory imperfections due to firing process, a tiny chip at about 7 o'clock (pic. #4) has been restored a long time ago.
A similar plate was sold in 2011 for $35,000, see the last photo.

Depicting the highest award, the Order of Saint Catherine or Order of Freedom. Only 700 individuals were bestowed by this order and only women with one exception, one man actually a boy, the son of the favorite of Peter I Menshikov.
It was the second established order after order of St. Andrew.
Peter the Great established this order in the memory of the event when he and his military men were surrounded by the Turks and Catherine, his mistress then, gave a bribe to the Turkish Commander by surrendering him all her jewelry in exchange for their freedom. A year after that she became
the wife of Peter I.
There are some other stories about this event, but this one looks more legit and much related to the establishment of the Order.